Comprehensive recovery of electric arc furnace dust: Mineral phase transformation and element migration

Electric arc furnace dust (EAFD) is both a valuable secondary resource and a hazardous solid waste in the metallurgical industry. In this work, the mineral phase transformation and element migration during the carbothermal reduction of EAFD under various temperature were systematically investigated. Furthermore, the thermodynamic mechanisms of Fe, Cr, and Mn metallization and alloying, as well as the removal and enrichment behaviors of high-vapor-pressure elements (Zn, Pb, K, Na, and Cl), were analyzed with a particular focus on ZnO-enriched powder. The results demonstrate that increasing the reduction temperature markedly enhanced the metallization of Fe, Mn, and Cr, leading to the formation of an Fe-Cr-Mn alloy. Simultaneously, high-vapor-pressure elements such as Zn, Pb, K, Na, and Cl were effectively removed and enriched in the ZnO-containing phase. K and Na are primarily removed in the form of chlorides, while Pb exists as both PbO and PbCl₂ in the ZnO-enriched powder. Notably, PbO progressively converts to PbCl₂ as the reaction temperature increases. This study offers insights into sustainable practices by contributing to the resource recovery of electric arc furnace dust, thereby supporting sustainable environmental management in the metallurgical industry, while also underscoring its economic potential through the production of high-value alloys and ZnO products and highlighting future directions for large-scale application and process optimization.